Sources tell the paper that Google is almost ready to submit its hypothetical standalone Google Maps application to the App Store, supplementing Apple's built-in and controversial Google-free Maps tool. Google has reportedly enlisted some external testers to put the app through its paces.

Of note, the WSJ story suggests that turn-by-turn navigation will be part of the new app's feature suite. The lack of turn-by-turn and voice navigation in the iOS 5-and-earlier Maps app (coded by Apple, powered by Google's data) was among the pain points that led Apple to build out its own mapping capability for iOS 6.

Having a Google-provided nav solution will help deliver parity with Google's maps tools on Android -- and will keep a portion of that location-based ad revenue and user monitoring data flowing back to the Googleplex.

The next question, of course, is whether or not Apple will release the Google mapping app via the App Store, or reject it back to Google. The two companies have not always seen eye-to-eye when it comes to iOS apps that shadow or replicate onboard functionality; the months of waiting for the official Google Voice app (and the third-party apps that were released, then rejected) are a prime example of the potential struggles, which would be magnified dramatically with the high profile of Maps. Our colleague Michael Grothaus reported in The Guardian that some Googlers are not optimistic about a rapid, drama-free App Store approval for the new Google Maps app.